With Brandon Boykin, Kurt Coleman and Colt Anderson all out with injuries, the Eagles were down to six healthy, active defensive backs at practice Tuesday.

Boykin, Coleman and Anderson were present at the Eagles’ indoor practice during the open media portion of practice, but were dressed in sweats, off to the side and were not participating in drills.

All three defensive backs got hurt in the Eagles’ 48-30 loss to the Vikings Sunday in Minneapolis.

Boykin suffered a concussion, Anderson a knee injury and Coleman a hamstring pull.

Safety Earl Wolff, who hasn’t played since the Packers game on Nov. 10 because of a knee injury, was participating in practice Tuesday, but according to defensive coordinator Bill Davis is still day-to-day. The rookie has missed four games.

Davis also called Coleman “week-to-week.”

The injuries left the Eagles with just cornerbacks Cary Williams, Bradley Fletcher, Curtis Marsh and Roc Carmichael, and safeties Patrick Chung and Nate Allen healthy and practicing.

Practice squad safety Keelan Johnson also participated in practice. Johnson ranked 11th in NCAA Division I last year with five interceptions for Arizona State.

The fact that Boykin was able to watch practice in the Eagles’ indoor bubble while loud music blasted from the huge overhead speakers was a very encouraging sign.

Generally, those recovering from a concussion are very sensitive to light and noise, so Boykin just being able to tolerate the music is an indication that he’s likely well along the recovery process.

Because most teams don’t practice on Tuesday, the NFL does not require teams to issue an official injury report until Wednesday.

The Eagles’ secondary was decimated both by injuries and by the Vikings Sunday.

Matt Cassel threw for 383 yards and two touchdowns for the Vikings. He became the first quarterback to throw for 350 or more yards and average over 10 1/2 yards per attempt against the Eagles since Joe Montana in 1989.

The Eagles rank 31st in the NFL in pass defense, allowing 291.6 yards per game. Only the Cowboys (297.4) are worse.